The field of the invention is wood screws and the invention relates more particularly to wood screws of the type which do not need to have a pilot hole drilled therefor.
Numerous attempts have been made over the years to facilitate the fastening of wooden objects. A novelty search revealed the suggestion of the addition of a spiral flute at a very early time. Such concept is shown in the U.S. Pat. Nos. 45,133, 142,112, 877,131 and 1,235,626. In spite of these early attempts, such screws have not found widespread use although the need for eliminating the time and inconvenience of drilling a pilot hole persists.
It is well known that simply driving a wood screw into wood without the provision of a pilot hole, particularly in hardwood, almost invariably results in the splitting of the wood. It also is very difficult to start the wood screw in a straight line.